Method of treating emery ore.



F..'I.TONB. METHOD OF TREATING EMBRY ORE.

APPLIOATION FILED NOV. 14, 1908.

1,002,608. 7 Patented Sept. 5, 1911.

62v7-M' M ZYQ WITNESSES ful Method of Treating TED STATES, PATENT oriuo.

FRANK J. TONE, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TO THE CARBORUNDUM COMPANY, OF vNIAGARA FALLS, NEW YORK, A. CORPORATION OF PENNSYLVANIA.

I METHOD OF TREATING- EMERY ORE.

nooasoe.

Specification of Letters Patent.

Patented Sept. 5, ion.

Application filed November 14, 1908. Serial No, 462,609.

To all whom it may concern;

Be it known that I, F ANKJ. TONE, of Niagara Falls, in Niagara county and State of New York, have invented a new and use- Emery Ore, of which the followin is a full, clear, and exact description, re erence being bad to the accompanying drawing, forming part of this specification, in which the figure is a longitudinal section showing one form of furnace for carrying out my invention.

My invention relates to the: treating and purifying of emery ore. This ore is a nat-.

ural one, consisting principally'of alumina,

but is always associated with impurities such as iron oxid, and usually silica, and often small quantities of titanium oxid and other impurities. These should be removed in order to convert the ore into a product consisting substantially of pure alumina, since this possesses increased hardness and greater abrasive qualities.

My improved process consists in a new mode of applying electric heat in connection with the use of sufficient carbonaceous material to reduce the impurities, this carbon.

being insuificient in quantity to reduce the alumina to a temperature below the reduction temperature of alumina and above the reduction temperature of silica.

In carrying out my process in its preferred form, a mixture is made of pulverized emery and carbon, the carbon being present to an amount suflicient to reduce all '35 the oxids other than alumina but insuflicient to reduce the alumina. The mass of mixture is then placed betweenthe electrode terminals of an electric furnace, and current is passed through the same. As the heating 40, of the mass progresses, and it becomes partially fused, its conductivity increases, and

when it reaches a well-fused condition the charge will become a good conductor of electricity. The current in passing through this mixture generates heat, and the furnace operates as a simple resistance furnace, the resistance conductor being tlfe fused charge. In the drawing, 2 represents a receptacle, preferably made of refractory material to contain the charge, and 3, 3 are the-electrode terminals connected with a source of electric current and depending in the furnace chamber at separated points. The lower ends of the electrodes make contact with the mass of mixture 4:, which is undergoing fusion, and is also in the process of'reduction.

ent product is obtained and one that is very friable, easily pulverized and not having properties making it a good abrasive.

The charge mixture 4 is supplied from time to time around and between the electrodes as it becomes reduced. I have found that the layer of fused and purified alumina 5 is a poor conductor of the-current, and that this current confines itself practically to the impure alumina shown the layer 4: which is undergoing reduction. Thus the distribution of current is self-adjusting, the major portion giving the proper heating effect where the most heat is required, allowin the purified product to cool very gradua ly and thus promoting crystallization in a most favorable manner. The electrodes are raised from time to time, as the column of the metallic rezone of fusion and reduction automatically raises itself above the purified layer and into the fresh charge. There is thus formed an ingot of the finished product to any hei ht desired. The reduction and fusion zone 01- lows the elevation of the electrodes, and in this way the process is practically continu ous. When an ingot of suflicient size has been formed the operation is stopped and the ingot is allowed to cool..- It is then broken up and crushed and the alumina separated from the metallic reduction product by concentration or other well known methods. If desired, instead of allowing the reduced metal to cool with the alumina, portions of the metallic reduction product which settle to the bottom of the furnace and remain in a fused condition may be tapped from time to time from the furnace through a suitable tap hole as shown at 6.

My invention presents many advantages over the arc method of heatih since a more moderate heat may be emp oyed and the temperature is regulated so asto reduce the iron silica and other impurities without attacking the alumina. When a charge of this character is submitted to the fullheat of an electric are it is impossible to reduce the iron and silica without also reducing a considerable portion of alumina;--and this disadvantage is obviated by my method.

- ess-has many valuable commercial uses. It

has great hardness and abrasive qualities, making it useful .in the manufacture of grinding wheels'where emery and corun dum have previously been used. It may be used for the further manufacture of aluminum compounds; It is very refractory and may be used .in fire brick, especially forbasic linings. The alloys of lI'OIl, silicon and titanium which are formed as reduction products in this process may also be used the metallurgy of iron and steel.

I claim 1. The process of treating emeryore, which consists in forming-.a mixture of pulverized ore with anamount of carbon sufiicient to reduce the constituents of the ore other than alumina, and insufiicient to reduce the alumina, interposing this mixture as a resistanceconductbr between electrodes andipassing current through the same at a temperature below the reduction temperature of alumina, and above the reduction temperature of silica, allowing the fused mass to. cool and separating the reduction products from the fused alumina, substantially as described.

2. The process of treating which consists in forming a mlxture of pulverized ore with an amount of carbon sufficient to reduce'the constituents of the ore other than alumina and insuflicient to reduce the alumina, interposing the mixture as a emery ore,

resistance conductor between electrodes and a passing ,current through the same at a tein-.

In testimony whereof, I have hereunto set.

my hand.

.. FRANK J. TONE.

Witnesses:

' ORLANDO B. WIL1vrsR,

" F. I. PIERCE. 

